1. Field of the Invention
The present invention relates to a method for forming a pattern, and a composition for forming a resist underlayer film.
2. Discussion of the Background
In producing elements of integrated circuits, a multilayer resist process has been employed nowadays in order to achieve a higher degree of integration. In brief, according to this process, a composition for forming a resist underlayer film is first coated on a substrate, thereby forming a resist underlayer film, on which a photoresist composition is coated to form a resist coating film, followed by transferring a mask pattern to the resist coating film using a reduced projection exposure system (stepper), etc., and developing with an appropriate developer to obtain a resist pattern. Thereafter, the resist pattern is transferred to the resist underlayer film by dry-etching. Finally, the resist underlayer film pattern is transferred to the substrate by dry-etching to enable a substrate having a desired pattern formed to be obtained.
In the aforementioned multilayer resist process, miniaturization of formed patterns has advanced, and thus further improvement of pattern transfer performances and etching resistance has been demanded for the resist underlayer film. To meet such demands, structures of polymers and functional groups included in polymers and the like contained in compositions for forming a resist underlayer film have been variously investigated (see Japanese Unexamined Patent Application, Publication No. 2004-177668).